1. Cleaning in a food environment

2. b Why Clean? b A little science  The role of water  surfactants b Choice of cleaning products b Terminal disinfectants b Miscellaneous issues b Procedures b Staff Training b Do’s and Don’ts b Conclusion

3. Why Clean? b Remove previous production b Avoid cross contamination b Equipment maintenance b Improve working environment b Customer demand b Avoid microbial contamination b Stay in business

4. A little science b Properties of water  High melting & boiling temperatures  High surface tension  High energy content  Expands on freezing  Effective solvent b These properties depend on the structure of the water molecule

5. Properties of water b Water molecule b One oxygen atom  eight protons & electrons b Two hydrogen atoms  one proton and electron b Electrons tend to be attracted to oxygen b Slight charge imbalance  Polar molecule

6. Properties of water b Water molecules are attracted to each other  Hydrogen bonding b Leads to a 3D Network which gives water some of its unique properties

7. Surface tension b Forces between water molecules;  Evenly balanced in centre  Uneven at surface b Resulting tension leads to problems with wetting

8. Detergents b Detergent molecules  Hydrophyllic (water loving) head  Hydrophobic (water hating) tail

9. Surfactants b Detergent molecule will form a layer on surface of an oil droplet  hydrophobic tail in the oil  hydrophyllic head in the water

10. Surfactants b Surplus detergent molecules cluster together in micelles with tails inward and heads outward

11. Surfactants b These surfactant properties of detergents lead to  lowering of surface tension leading to improved wetting  loosening of dirt on a surface  holds oil in suspension  prevents redeposition of dirt

12. Types of surfactant b Anionic  Common general purpose cleaners  Often alkaline in solution b Non-ionic  milder cleaning action  rarely used on their own b Cationic and amphoteric  not generally used as cleaning agents  can act as biocides

13. Choosing cleaning products b Cleaning regime  Type of clean (open plant? CIP?)  Standard of cleaning required  Types of soil  Typical microbial contamination  Risks  of contaminating the food  to people (COSHH)  to equipment  Resources: labour, time, equipment  Environmental: effect on effluent

14. Basic Cleaning Procedure b Preparation  Removal of gross dirt b Cleaning  Main cleaning stage b Rinsing b Disinfection b Rinsing  May be omitted if sanitiser designed to be left on

15. Types of clean b Dry clean  removal of dirt by physical means b Hand clean  use neutral or mildly alkaline cleaners plus physical energy  ensure cleanliness of cleaning equipment b Soak clean  Enhance contact time for bad soil  Detergents often very alkaline  special formulations sometimes needed  e.g. with aluminium

16. Types of clean b Foam or gel clean  Enhances contact time  Alkaline detergents usually used  Chlorinated caustic products effective on proteins  Still needs physical energy to remove dirt  Care needs to be taken with spray washdown systems

17. Types of clean b Automated washing machines  used for trays, racks, bins, utensils etc.  use alkaline detergents for plastics and steel  neutral or specially formulated detergents for aluminium b Cleaning in place  Often uses very aggressive chemicals  Usually caustic/sequestrating  Acid formulations effective on some soils

18. Material issues b Plastics may be susceptible to stress corrosion cracking with neutral/alkaline detergents b Soft metals such as aluminium or brass may be attacked by detergents  Should use special formulations

19. Terminal disinfectants b Should specify to deal with likely micro- organisms b Often inactivated by detergents  thorough rinsing essential before disinfection b Quaternary ammonium compounds widely used  they are relatively low cost  few problems with taint  not effective against all micro-organisms esp. gram negatives such as listeria

20. Terminal disinfectants b Amphoteric surfactants  More expensive  effective against gram negative bacteria  Some suppliers are now offering dual biocides b To rinse or not to rinse?  UK law permits you to leave terminal disinfectants on your equipment without rinsing  EC regulations require a final rinse to remove terminal disinfectants  Which is preferable?

21. Procedures & Documentation b Cleaning Schedules  What? When? How? b Documentation  Keep proper records  Ensure records are accurate (due diligence) b Hygiene testing  Rapid or traditional?

22. Documentation b Detail: Through the day, daily, weekly, monthly, quarterly, annual b Involve hygiene staff in detail of production of routines b Agree correct names of machines b Use checklists to record who cleaned what and when

23. Hygiene Testing b Rapid or traditional? b Rapid  results in a few minutes  production tool  clearance after cleaning  Part of HACCP b Traditional  Part of QC  Established and known  Identifies organisms

24. Training b Cleaning is start of process not end  Start with a clean plant  Do not relegate inept staff to cleaning team b Be aware of new chemicals/processes b Rotate staff round whole factory b Feedback good results don’t just complain about bad ones! b Ensure trainers are properly trained.  Accreditation via outside approved organisations

25. What can go wrong? b Untrained people b Inappropriate chemicals and equipment  rotate terminal disinfectants b Water problems b Poor safety equipment b Poor cleaning/storage of equipment b Pressure on production

26. What can go right? b Build in cleaning at design stage b Proper engineering of equipment b Clean correctly and  Stay in business  build reputation  open new markets

27. Miscellaneous issues b Choice of supplier  Select supplier with good backup  Work with supplier on technical issues b Testing for cleanliness  Traditional microbiological testing is reliable but time consuming  Rapid methods give quick results, and give confidence for restart  Based on detecting biological materials

28. Concluding comments b Effective cleaning depends on  An understanding of materials and equipment  Effective relationships with suppliers  Effective systems which operate in practice b Above all it should be part of a culture of hygiene within the company